A composition comprising a 1,2-polyepoxide and piperidine derivitive as curing agent

ABSTRACT

The new compound 4-amino-3-aminomethylpiperidine is manufactured by hydrogenating 4-amino-3-cyano-1,2,5,6-tetrahydropyridine in a manner which is in itself known. The 4-amino-3-cyano-1,2,5,6tetrahydropyridine used as the starting substance can be obtained by cyclisation of bis-cyanoethylenated ammonia. The new compound 4-amino-3-aminomethylpiperidine represents a valuable curing agent for epoxide resins, and advantageously 0.5 to 1.3 equivalents of nitrogen-bonded active hydrogen atoms of the 4amino-3-aminomethylpiperidine are used per 1 equivalent of epoxide groups of the polyepoxide compound.

United States Patent Zondler et a1.

[ 1 Feb. 20, 1973 A COMPOSITION COMPRISING A 1,2-

- POLYEPOXIDE AND PIPERIDINE DERIVITIVE AS CURING AGENT Inventors:Helmut Zonflgr Allschwil, Switzerland; Wolfgang Pfleideren, Co nstance,Germany Assignee: Ciba-Geigy AG, Basle, Switzerland Filed: March 17,1971 Appl. No.: 125,382

Foreign Application Priority Data March 23, 1970 Switzerland ..4337/70US. Cl. ..260/2 N, 106/311, 117/161 28, 161/184, 260/9, 260/28, 260/304EP,

260/47 EN, 260/59, 260/775 NC, 260/784 EP, 260/293, 260/831, 260/834,260/836 Int. Cl. ..C08g 30/14 Field of Search ..260/2 N, 47 EN, 78.4 EP,293 D, 293 Z, 77.5 NC

[56] References Cited UNITED STATES PATENTS 3,544,590 12/1970 Kittleson..260/2 Primary Examiner-William H. Short Assistant Examiner-T. PertillaAttorney-Harry Goldsmith, Joseph G. Kolodny,

Mario A. Monaco and Stanley A. Marcus ABSTRACT 1.3 equivalents ofnitrogen-bonded active hydrogen at6rns of the4-amino-3-aminomethylpiperidine are used per 1 equivalent of epoxidegroups of the polyepoxide compound.

8 Claims, No Drawings A COMPOSITION COMPRISING A 1,2- POLYEPOXIDE ANDPIPERIDINE DERIVITIVE AS CURING AGENT The subject of the presentinvention is the new compound 4-amino-3-aminomethyl-piperidine of theformula NHz H 0Q? fio-omavm LE2 H2 The compound of the formula (I) canbe manufactured, according to the invention, by hydrogenating 4-amino-3-cyano-l,2,5,6-tetrahydropyridine of the formula NH2 J; 01 12\C-JJEN (3E2 /(!)1 2 PNI n in a manner which is in itself known.

The hydrogenation preferably takes place in the presence of a catalyst.Raney nickel or Raney cobalt are particularly effective as hydrogenationcatalysts. It is also possible to use a cobalt oxide catalyst on asuitable carrier material, this catalyst being reduced to cobalt metalcatalyst in the stream of hydrogen.

Further possible hydrogenation catalysts are catalysts based on platinumand palladium which can be employed as platinum black or palladiumblack, as colloidal platinum or palladium, or as platinum oxide orpalladium oxide, or platinum hydroxide or palladium hydroxide,catalysts. Possible carrier materials for such catalysts are thecustomary materials, such as asbestos, pumice, kieselguhr, silica gel,silica, active charcoal, and the sulphates, carbonates or oxides of themetals of Groupsll to VIII of the periodic system, especially ofmagnesium, calcium, barium, zinc, aluminum, iron, chromium andzirconium.

The hydrogenation can be carried out according to the methods which arecustomary in the laboratory and in industry, either without pressure,for example in a duck-shaped shaking vessel, or under pressure in anautoclave. Solvents which can be used in the hydrogenation are theorganic solvents which are customarily employed together with theabovementioned types of catalyst, and in particular, preferably, loweraliphatic alcohols, such as methanol or ethanol.

The catalytic reduction is as a rule carried out by mixing thesuspension or solution of the 4-amino-3- cyano-l,2,5,6-tetrahydropyridine with the catalyst and passing hydrogen gasinto the reaction mixture. The hydrogenation can in principle be carriedout at atmospheric pressure and room temperature, but elevated pressuresof 50 atmospheres and above, and elevated reaction temperatures in therange of 50 to 150 C are preferred. The hydrogenation is continued untilno further hydrogen is absorbed. After completion of the hydrogenationthe catalyst is separated off, for example by filtration, and thesolvent is distilled off.

The hydrogenation can also be carried out according to other knownmethods, for example by treatment with alkali metals, such as metallicsodium, in alcoholic solution.

The 4-amino-3-cyano-l ,2,5 ,6-tetrahydropyridine used as a startingsubstance can be obtained by cyclization of bis-cyanoethylated ammoniaof the formula CH CHPCN The new compound 4-amino-3-aminomethylpiperidinerepresents a valuable curing agent for epoxide resins.

A further subject of the present invention are thus curable mixtureswhich are suitable for the manufacture of shaped articles,impregnations, coatings and adhesive bonds and which are characterizedin that they contain a) a polyepoxide compound with an average of morethan one epoxide group in the molecule and b) 4-amino-3-aminomethyl-piperidine as the curing agent.

Appropriately, 0.5 to 1.3 equivalents, preferably approx. 1.0equivalent, of nitrogen-bonded active hydrogen atoms of the4-amino-3-aminomethylpiperidine are used per 1 equivalent of epoxidegroups of the polyepoxide compound (a).

Possible polyepoxide compounds (a) are above all those with an averageof more than one glycidyl group, B-methyl-glycidyl group or2,3-epoxycyclopentyl group bonded to a hetero-atom (for example sulphur,preferably oxygen or nitrogen); in particular, there may be mentionedbis-(2,3-epoxycyclopentyl)ether; diglycidyl ethers and polyglycidylethers of polyhydric aliphatic alcohols, such as 1,4-butanediol, orpolyalkylene glycols, such as polypropylene glycols; diglycidyl ethersor polyglycidyl ethers of cycloaliphatic polyols, such as2,2-bis-(4-hydroxycyclohexyl)propane; diglycidyl ethers and polyglycidylethers of polyhydric phenols, such as resorcinol, bis-(phydroxyphenyl)methane, 2,2-bis(p-hydroxyphenyl) propane (=Diomethan),2,2-bis(4'-hydroxy-3', 5' dibromophenyl)-propane, 1,1,2,2,-tetrakis-(p-hydroxy-phenyl)-ethane or of condensation products ofphenols with formaldehyde, obtained under acid conditions, such asphenol novolacs and cresol novolacs; diand poly-(B-methylglycidyl)ethers of the abovementioned polyhydric alcohols or polyhydric phenols;polyglycidyl esters of polybasic carboxylic acids, such as phthalicacid, terephthalic acid, A- tetrahydrophthalic acid andhexahydrophthalic acid; N-glycidyl derivatives of amines, amides andheterocyclic nitrogen bases, such as N,N-diglycidyl-aniline,N,N-diglycidyl-toluidine, andN,N,N',N-tetraglycidylbis-(p-aminophenyl)-methane;triglycidylisocyanurate, N,N-diglycidyl-,5-dimethyl-hydantoin, N,N'-diglycidyl-5-isopropyl-hydantoin; N,N-diglycidyl-5,5-dimethyl-6-isopropyl-5 ,o-dihydro-uracil.

If desired, active diluents, such as for example, styrene oxide, butylglycidyl ether, isooctyl glycidyl ether, phenyl glycidyl ether, cresylglycidyl ether or glycidyl esters of synthetic, highly branched, mainlytertiary aliphatic monocarboxylic acids (CARDURA E") can be added to thepolyepoxides to reduce the viscosity.

The curing of the curable mixtures according to the invention to giveshaped articles and the like is appropriately carried out in thetemperature range of 20 to 150 C. The curing can also be carried out ina known manner in two or more stages, with the first curing stage, forexample, being carried out at room temperature and the post-curing beingcarried out at a higher temperature.

The curing can, if desired, also be carried out in 2 stages by firstprematurely stopping the curing reaction or carrying out the first stageat room temperature or only slightly elevated temperature, whereby acurable precondensate (so-called B-stage) which is still fusible andsoluble is obtained from the epoxide component (a) and the amine curingagent (b). Such a precondensate can for example serve for themanufacture of prepegs, compression moulding compositions or especiallysintering powders.

In order to shorten the gelling times or curing times, knownaccelerators for curing with amines, for example monophenols orpolyphenols, such as phenol or diomethane, salicylic acid, tertiaryamines or salts of thiocyanic acids, such as NH SCN, can be added.

The term cure as used here denotes the conversion of the soluble, eitherliquid or fusible, polyepoxides into solid, insoluble and infusible,three-dimensionally cross-linked products or materials, and inparticular, as a rule, with simultaneous shaping to give shapedarticles, such as castings, pressings, laminates and the like, orsheet-like structures, such as coatings, lacquer films or adhesivebonds.

The curable mixtures according to the invention are polyepoxidecompounds (a) and 4-amino-3- aminomethyl-piperidine as the curing agentcan further be mixed, in any stage before curing, with customarymodifiers, such as extenders, fillers and reinforcing agents, pigments,dyestuffs, organic solvents, plasticizers, flow control agents,flameproofing substances or mould release agents.

As extenders, reinforcing agents, fillers and pigments which can beemployed in the curable mixtures according to the invention there may,for example, be mentioned: coal tar, bitumen, textile fibers, glassfibers, asbestos fibers, boron fibers, carbon fibers, cellulose,polyethylene powder, polypropylene powder; quartz powder, mineralsilicates, such as mica, asbestos powder and slate powder; kaolin,aluminum oxide trihydrate, chalk powder, gypsum, antimony trioxide,bentones, silica aerogel (AEROSIL), lithopone, baryte, titanium dioxide,carbon black, graphite, oxide colors, such as iron oxide, or metalpowders, such as aluminum powder or iron powder.

Suitable organic solvents for modifying the curable mixtures are, forexample, toluene, xylene, n-propanol, butyl acetate, acetone, methylethyl ketone, diacetonealcohol, ethylene glycol monomethyl ether,monoethyl ether and monobutyl ether.

Dibutyl phthalate, dioctyl phthalate and dinonyl phthalate, tricresylphosphate, trixylenyl phosphate and also polypropylene glycols can forexample be employed as plasticizers for modifying the curable mixtures.

Silicones, cellulose acetobutyrate, polyvinyl butyral, waxes, stearatesand the like (which are in part also used as mould release agents) canfor example be employed as flow control agents when using the curablemixtures, especially in surface protection.

For use in the lacquer field, in particular, the polyepoxide compoundscan further be partially esterified in a known manner with carboxylicacids, such as, especially, higher unsaturated fatty acids. It isfurthermore possible to add other curable synthetic resins, for examplephenoplasts or aminoplasts, to such lacquer resin formulations.

The curable mixtures according to the invention can be manufactured inthe customary manner with the aid of known mixing equipment (stirrers,kneaders, rolls and the like).

The curable epoxide resin mixtures according to the invention are aboveall employed in the fields of surface protection, the electricalindustry, laminating processes and the building industry. They can beused, in each case in a formulation adapted to the particular end use,in the unfilled or filled state, and optionally in the form of solutionsor emulsions, as paints, lacquers, sintering powders, compressionmoulding compositions, injection moulding formulations, dipping agents,casting resins, impregnating resins, binders and adhesives, tool resins,laminating resins, sealing and filling compositions, floor coveringcompositions and binders for mineral aggregates.

In the examples which follow, unless otherwise indicated, parts denoteparts by weight and percentages denote percentages by weight. Therelationship of parts by volume to parts by weight is as of themilliliter to the gram.

The following epoxide resins were used for the manufacture of curablemixtures described in the examples.

Epoxide Resin A Diglycidal ether resin (technical product) manufacturedby condensation of diomethane (2,2-bis(phydroxyphenyl)-propane) with astoichiometric excess of epichlorohydrin in the presence of alkali,consisting mainly of diomethane-diglycidyl ether of the formula which isliquid at room temperature and has the following characteristics:

Epoxide content: 5.1 5.5 epoxide equivalents/kg Viscosity (Hoeppler) at25 C: 9000 13,000 cP.'

Epoxide Resin B Diglycidyl ether resin (technical product) manufacturedby condensation of hydrogenated diomethane(2,2-bis-(p-hydroxycyclohexyl)-propane) with a stoichiometric excess ofepichlorohydrin in the presence of alkali, consisting mainly ofhydrogenated diomethane-diglycidal ether of the formula which is liquidat room temperature and has an epoxide content of 4.46 epoxideequivalents/kg.

Epoxide Resin C Tetrahydrophthalic acid diglycidyl ester having thefollowing characteristics:

Epoxide content: 6.45 equivalents/kg Viscosity (Hoeppler) at 25 C:450-550 cP.

To determine the mechanical and electrical properties of the mouldingswhich can be manufactured from the curable mixtures described in theexamples which follow, sheets of size 135 X 135 X 4 mm were manufacturedfor determining the flexural strength, deflection, impact strength andwater absorption. The test specimens (60 X X 4 mm) for determining thewater absorption and for the flexura] test and impact test (VSM 77,103and VSM 77,105) were machined from the sheets.

Manufacturing Example 4-Amino-3-aminomethyl piperdine a. 160 g of4-amino-3-cyano-l,2,5,6-tetrahydropyridine in 600 ml of ethanol arehydrogenated over the course of 4 hours with Raney nickel, activatedwith 2 percent of palladium, at l-l30 C and approx. 100 atmospheres Hpressure in an autoclave. After removing the catalyst and the solvent,the product is fractionated through a cm long packed column. Yield: 58.3g (35.0%); boiling point 126-29 C/10 mm Hg. The amine forms a dipicrateof melting point 229 C (decomposition) which can be recrystallized fromethanol with addition of a little water.

Analysis: C H N 2 C H N O (M 587.42).

Calculated: C 36.80 H 3.61 N 21.46

Found C 37.31 H 3.62 N 20.82

b. 110.7 g of 4-amino-3-cyano-l,2,5,6-tetrahydropyridine in a mixture of300 ml of ethanol and 100 g of ammonia are hydrogenated over the courseof 5 hours with 10 g of Raney nickel at l15-120 C and a pressure of 100atmospheres in an autoclave. After removing the catalyst and thesolvent, the mixture is first distilled in vacuo without a column,whereby 91.4 g of crude amine of boiling point 150 C/7 mm Hg areobtained. The fractional distillation through a rotating strip columnyields 82.0 g (70.7 percent) of pure amine of boiling point 1141l6 C/6.5mm Hg.

Analysis: C H N (M= 129.21)

Calculated: C 55.78 H 11.70 N 32.52

Found C 55.73 H 11.80 N 32.67

4-Amino-piperidine can be detected as a by-product in the firstrunnings.

4-Ami'no-3-aminomethyl-piperidine forms a dipicrate of melting point 229C (decomposition) and was analyzed as such, after recrystallization fromethanol with the addition of a little water.

Analysis: C H N 2 C l-i N O, (M= 587.42)

Calculated: C 36.80 H 3.61 N 21.46

Found C 37.31 H 3.62 N 20.82 NMR-spectrum in deuterateddimethylsulphoxide:

Mass spectrum:

The molecular peak at m/e 129 does not show up. Instead, a fragment,corresponding to splitting off NH appears at m/e 112. The mass spectrumof the free amine also shows the heaviest fragment of mass m/e 112.

IR-spectrum:

Band [cm-'1 Interpretation 3370 m. NH, stretching vibration 3290 m. NH,stretching vibration 3200 shoulder Harmonic vibration of 1600 em 1600 m.NH, deformation vibration Use Examples Example I parts of epoxide resinA and 9.5 parts of 4-amino- 3-aminomethyl-piperidine (corresponding to aratio of epoxide equivalents: nitrogen-bonded active H atoms 1011.0)were mixed at room temperature (25 C), degassed in vacuo and poured intoaluminum moulds.

The mixture gelled, with an exothermic temperature rise. After cooling,it was post-cured for a further 24 hours at C.

The castings obtained had the following properties:

Flexural strength according to VSM 77,103 10.6

Deflection according to VSM 77,103 5.6 mm

Impact strength according to VSM 77,105 7.7

emkg/cm Example 11 224 parts of epoxide resin B and 25.8 parts of 4-amino-3-aminomethyl-piperidine were mixed at room temperature (25 C),degassed in vacuo, then poured into prewarmed aluminum moulds of size X140 X 4 mm and subsequently heated for 4 hours to 80 C and 12 hours to140 C. The resulting shaped articles had the following properties:

Heat distortion point according to DIN 53461 Flexural strength accordingto VSM 77,103 11.4

kg/mm Deflection according to VSM 77,103 6.4 mm

Impact strength according to VSM 77,105 6.8

Tensile strength according to VSM 77,101 -3.4

Elongation at break according to VSM 77,101 6.7

percent Glass transition temperature* 1 1 1 C measured in theDifferential Scanning Calorimeter (DSC-l using a speed of heating of 16C/min.

Example III parts of epoxide resin C and 25.8 parts of 4-amino-3-aminomethyl-piperidine were mixed and further processed as inExample 11.

The shaped articles obtained had the following properties:

Heat distortion point according to DIN 53461 Flexural strength accordingto VSM 77,103 10.5

kg/mm Deflection according to VSM 77,103 3.6 mm

Impact strength according to VSM 77,105 12.7

cmkg/cm Tensile strength according to VSM 77,101 3.6

kg/mm Elongation at break according to VSM 77,101 6.0

percent Glass transition temperature (DSC-l 127 C We claim:

1. A composition of matter which contains (a) a polyepoxide with anaverage of more than one l,2- epoxide group in the molecule and (b)4-amino-3- aminomethyl-piperidine as the curing agent, said compositioncontaining 0.5 to 1.3 equivalents of nitrogenbonded active hydrogenatoms of 4-amino-3- aminomethyl-piperidine (h) per 1 equivalent ofepoxide groups of the polyepoxide (a).

2. A composition as claimed in claim 1, which contains approximately 1.0equivalent of nitrogen-bonded active hydrogen atoms of4-amino-3-aminomethylpiperidine (b) per 1 equivalent of epoxide groupsof the polyepoxide (a).

3. A composition asclaimed in claim 1, which contains a polyglycidylether of a polyhydric phenol as the polyepoxide (a).

4. A composition as claimed in claim 3, which contains a polyglycidylether of 2,2-bis-(p-hydroxyphenyl)- propane as the polyepoxide (a).

5. A composition as claimed in claim 1, which contains a polyglycidylester of a polycarboxylic acid as the polyepoxide (a).

6. A composition as claimed in claim 5, which contains the diglycidylester of -tetrahydrophthalic acid or hexa-hydrophthalic acid as thepolyepoxide (I 7. A composition as claimed in claim 1, which contains apolyglycidyl ether of a cycloaliphatic polyol as the poly polyepoxide(a).

8. A composition as claimed in claim 7, which contains the diglycidylether of 2,2-bis-(4'-hydroxycyclohexyl)-propane as the polyepoxide (a).

1. A composition of matter which contains (a) a polyepoxide with anaverage of more than one 1,2-epoxide group in the molecule and (b)4-amino-3-aminomethyl-piperidine as the curing agent, said compositioncontaining 0.5 to 1.3 equivalents of nitrogen-bonded active hydrogenatoms of 4-amino-3-aminomethyl-piperidine (b) per 1 equivalent ofepoxide groups of the polyepoxide (a).
 2. A composition as claimed inclaim 1, which contains approximately 1.0 equivalent of nitrogen-bondedactive hydrogen atoms of 4-amino-3-aminomethyl-piperidine (b) per 1equivalent of epoxide groups of the polyepoxide (a).
 3. A composition asclaimed in claim 1, which contains a polyglycidyl ether of a polyhydricphenol as the polyepoxide (a).
 4. A composition as claimed in claim 3,which contains a polyglycidyl ether of 2,2-bis-(p-hydroxyphenyl)-propaneas the polyepoxide (a).
 5. A composition as claimed in claim 1, whichcontains a polyglycidyl ester of a polycarboxylic acid as thepolyepoxide (a).
 6. A composition as claimed in claim 5, which containsthe diglycidyl ester of 4-tetrahydrophthalic acid or hexa-hydrophthalicacid as the polyepoxide (1).
 7. A composition as claimed in claim 1,which contains a polyglycidyl ether of a cycloaliphatic polyol as thepoly polyepoxide (a).